Use the content below and overwrite the existing /etc/sysconfig/ip6tables. # everything else coming from outside will be dropped A INPUT -p tcp -m tcp -dport 22 -m state -state NEW -j ACCEPT # by default, we allow new SSH connections on port 22 all interfaces - we may want to change that and be more selective A INPUT -m state -state ESTABLISHED -j ACCEPT # established connections initiated by us are accepted # anything that comes from us through the loopback interface is accepted # the default OUTPUT chain policy is to ACCEPT unless there's a rule that explicitly rejects or drops the packet # the default FORWARD chain policy is to DROP unless there's a rule that explicitly accepts the packet # the default INPUT chain policy is to DROP unless there's a rule that explicitly accepts the packet Use the content below and overwrite the existing /etc/sysconfig/iptables. 8 Allow Incoming Connections Only from Hosts on a Specific Subnet.7.1 Allow UDP Traffic for a Specific Port.5 Allow a Web Server on a Specific Interface.

4 Allow SSH Only From the Internal Network on a Non-Standard Port.

Iptables input